Influence of metal ions on bioremediation activity of protocatechuate 3,4-dioxygenase from Stenotrophomonas maltophilia KB2

The aim of this paper was to describe the effect of various metal ions on the activity of protocatechuate 3,4- dioxygenase from Stenotrophomonas maltophilia KB2. We also compared activity of different dioxygenases isolated from this strain, in the presence of metal ions, after induction by various aromatic compounds. S. maltophilia KB2 degraded 13 mM 3,4-dihydroxybenzoate, 10 mM benzoic acid and 12 mM phenol within 24 h of incubation. In the presence of dihydroxybenzoate and benzoate, the activity of protocatechuate 3,4-dioxygenase and catechol 1,2-dioxygenase was observed. Although Fe3?, Cu2 ?, Zn2?, Co2 ?, Al3 ?, Cd2 ?, Ni2 ? and Mn2? ions caused 20–80 % inhibition of protocatechuate 3,4-dioxygenase activity, the above-mentioned metal ions (with the exception of Ni2?) inhibited catechol 1,2-dioxygenase to a lesser extent or even activate the enzyme. Retaining activity of at least one of three dioxygenases from strain KB2 in the presence of metal ions makes it an ideal bacterium for bioremediation of contaminated areas

Bacterial properties changing under Triton X-100 presence in the diesel oil biodegradation systems : from surface and cellular changes to mono- and dioxygenases activities

Triton X-100, as one of the most popular surfactants used in bioremediation techniques, has been reported as an effective agent enhancing the biodegradation of hydrocarbons. However efficient, the surfactant’s role in different processes that together enable the satisfying biodegradation should be thoroughly analysed and verified. In this research, we present the interactions of Triton X-100 with the bacterial surfaces (hydrophobicity and zeta potential), its influence on the enzymatic properties (considering mono- and dioxygenases) and profiles of fatty acids, which then all together were compared with the biodegradation rates. The addition of various concentrations of Triton X-100 to diesel oil system revealed different cell surface hydrophobicity (CSH) of the tested strains. The results demonstrated that for Pseudomonas stutzeri strain 9, higher diesel oil biodegradation was correlated with hydrophilic properties of the tested strain and lower Triton X-100 biodegradation. Furthermore, an increase of the branched fatty acids was observed for this strain

Potato Protein-Based Vegan Burgers Enriched with Different Sources of Iron and Fiber: Nutrition, Sensory Characteristics, and Antioxidants before and after In Vitro Digestion

The aim of this research was to develop a technology for the production of plant-based burgers (PBBs) based on potato protein, also containing high content of iron and appropriately selected fats. The produced PBBs were characterized in terms of their nutritional and bioactive properties both before and after the in vitro digestion process. It was found that the produced burger was characterized by high protein content, ranging from 20.80 to 22.16 g/100 g. It was also shown to have a high dietary fiber content, ranging from 8.35 to 9.20 g/100 g. The main fraction of dietary fiber in the tested samples was insoluble fiber, which accounted for approximately 89% of the total fiber content. In addition, noteworthy is the high digestibility of the protein, reaching approximately 95% for the potato fiber used in the formulation, and about 85% for the oat fiber. Produced PBBs also provide significant amounts of iron, with the use of an organic iron source greatly increasing its quantity in the final product. The analyzed antioxidant properties before and after the digestion process showed a tenfold increase in biological activity after digestion, indicating that the examined PBBs may counteract oxidative stress. Analyzing the chemical and biological properties, it is impossible not to assess consumer attractiveness. It has been shown that PBB1, which contains potato fiber and powdered sprouts enriched with ferritin, received the highest attractiveness ratings among respondents

Influence of metal ions on bioremediation activity of protocatechuate 3,4-dioxygenase from Stenotrophomonas maltophilia KB2

The aim of this paper was to describe the effect of various metal ions on the activity of protocatechuate 3,4-dioxygenase from Stenotrophomonas maltophilia KB2. We also compared activity of different dioxygenases isolated from this strain, in the presence of metal ions, after induction by various aromatic compounds. S. maltophilia KB2 degraded 13 mM 3,4-dihydroxybenzoate, 10 mM benzoic acid and 12 mM phenol within 24 h of incubation. In the presence of dihydroxybenzoate and benzoate, the activity of protocatechuate 3,4-dioxygenase and catechol 1,2-dioxygenase was observed. Although Fe(3+), Cu(2+), Zn(2+), Co(2+), Al(3+), Cd(2+), Ni(2+) and Mn(2+) ions caused 20–80 % inhibition of protocatechuate 3,4-dioxygenase activity, the above-mentioned metal ions (with the exception of Ni(2+)) inhibited catechol 1,2-dioxygenase to a lesser extent or even activate the enzyme. Retaining activity of at least one of three dioxygenases from strain KB2 in the presence of metal ions makes it an ideal bacterium for bioremediation of contaminated areas